Apparatus for setting blind rivets



Aug. 13, 1946. E, H, H FF 2,405,613

APPARATUS FOR SETTING BLIND RIVE'I'S Original Filed Nov. 5, 1942 INVENTOR. fP/VES? 5/7 4 75 I BY; L

Arr-mew! Y Patented Aug. 13, 1946 APPARATUS FOR SETTING BLIND VRIVETS ErnestH. Shalf, Spring Lake, Mich., assignor to Cherry Rivet Company, Los ,Angeles, Calif., a corporation of California Original application November 1942, Serial No. 464,677. Divided and this application April 30,

1945, Serial No. 591,039

3 Claims.

"This invention relates to blind rivets and has particular reference to apparatus for setting blind rivets of the type in which the rivet setting stem or mandrel is provided with helical threads 2 ther shown in connection with the parts to be fastened together;

Fig. 2 is a fragmentar longitudinal sectional view illustrating the method and means for anadapted to cut corresponding threads in -the'rivet 6 plying the rivet; body as the stem is drawnthrough the rivet in the Fig. 3 is a fragmentary longitudinal sectional rivet settingoperation. View of the improved rivet with its forming stem This application is a division of my copendmodified for cooperation with aslightly ,di-fierent ing application Serial No. 464,677, filed November form of tool; and 5, 1942, now Patent Number 2,385,886, granted Fig. 4is a similar view but showing'therelation Oct. "2, 1945, which describes and claims a rivet of the parts after th rivet has been set. of thecharacter set forth above. The rivet assembly comprises two principal 'In my copendi-ngapplication serial No. 464,677 parts, namely, the rivet proper or rivet body and noted above, there 'is described and illustrated a its forming stem. The rivet proper consists of a form ofblind rivet which comprises a hollow rivet 1 tub lar sh nk '1 h vi g he d '8 at its outer end. body adapted to be inserted into rivet holes in The shank 'T has a smooth axial bore through sheetaor other devices to which the rivet is to'be which is inserted a form stem ;9 having t 1 attached, with a stem extending through the rivet inner end a forming head l0 .andat its outer .end'a body including a portion comprising a forming section I I specially constructed to permit of a head, immediately adjacent to which the stem, is firm gripping action on the stem. The head in provided with one :or more helical threads exis'of a diameter adapted to .be entered through tending outwardly from'the body of the stem and registering holes l2 in two plates vcl parts A and adapted, when the stem is :drawn inwardly of the B which are to bef sten d tog th r. rivet :body and partially rotated, to cut corre- The for-min s em 9 is provided near the head sponding threads in the rivet body while at the in with a portion I 3 of an external diameter same time expanding the rivet body radially to somewhat larger than the internal diameter vof perform the triple iunctionof enlarging the rivet the rivet bore and having one 1 mor r lly body radially to insure tight fit within the rivet extending heli ribs e ds fo m d thereon holes, upsetting the innerend of the rivet body to and operative when the forming stem is withhold the rivet securely in place, and .to threadedly rawn "a y through the shank 1 to exert -'a engage the stem and rivetbody to insure retention of the stem within the deformed rivet body.

It is an object of this invention to provide an apparatus by which the rivet stem may be given the necessary axial pull and rotary motion to properly set a rivet of the type described and claimed .in the above noted application.

.Another object of my invention is to provide apparatus by which the stem of a rivet of the character described maybe drawn axially relative to the rivet body and simultaneously given the rotational :movementnecessary to set the rivet.

Another object of this invention is to provide an apparatus of the character described in the preceding paragraph where'inthe axial and-rotary motions are so coordinated with each other as to conform with the *pitcho'f the threads on the rivet stem;

Other objects and advantages of my invention will be apparent :from a study of the following specification, read in connection withthe accompany-ing drawing, wherein Fig. 1 is a longitudinal sectional view through a tubular rivet and showing its cooperating forming member in elevation, the assembly being furill) radial expansive force upon :the shank which serves :not only to bind the forming stem in the shank but also to expand the latter .intolen-gagement with the edges of the holes 12 of the parts A and B.

In the operation of upsetting the inner end of the tubular shank '7, a combined axial and rota.- tional movement is imparted to the forming stem 9. As will be seen from a comparison-oi Figs. 1 and 2, the helically threaded portion 1 3 is in this operation first moved into intimate binding engagement with the rivet shank 1, and upon engagement between the iorming head -lllof the stem and the inner end of the shank l. the continued rotational and axial movement imparted to :the forming stem causes the helically threaded portion l3 to-continue its movement with ascrew feed during the upsetting operation. As a result, the upsetting is performed not on ly becausevo'f an axial movement imparted to the stem but by a, rotary screw threading action substantially laugmenting the force required to be applied axially to perform the upsetting operation.

Referring now to Fig. 2, I have provided a preferred form of puller for use in applying the ing cone H rivet. This device comprises a tool'body formed as a cylindrical casing l4 internally threaded as at 15 to receive a screw actuator 16. The inner end of the actuator is provided with a suitable chuck ll for gripping the outer serrated end of the forming stem 9. The chuck: jaws are yielda-bly held contracted by means of a spring pressed plunger l9 cooperating with a contract- The actuator IB may be rotated in any suitable way as by means of a squared shaft 29 operated either manually or by a suitable source of power. The forward end of the casing or body I4 has a cap 2! apertured for the passage of the forming stem 9, and when the actuator is advanced to the front end of the casing the chuck jaws engage with the cap and are forced rearwardly in the actuating cone l'l to permit of insertion and removal of the forming stem. The cap 2| also has formed integral therewith a concave recess 22 shaped to form alseat forthe head 8'.

In applying the rivet, the serrated end H of theiormingv stem is inserted into the chuck I1 oti thelpuller. Th rivet assembly is then inserted through the alined holes l2 in the parts A-.and B, and with the concave nose 22 of the tool; engaging withthe head 8, a rotary motion i'siimparted to the shaft 20. As the screw i6 is turned, the end portion H of the forming stem is gripped by. the jaws offthe chuck H which are coincidentally forced by the contracting cone [l c-tightly into firm gripping engagement with thetstemf i-Au'combined rotational and axial force is thusimparted to the forming stem and as the latter. is drawn through the tubular shank, the head .10 thereof is forced axially and simultaneou'sl'y: rotated so as toupset the inner end of the itubular rivet shank with a rolling motion. Coincidentally, the threaded portion l3 of the stem; beingof an external diameter somewhat largerthan the internal diameter of the shank, forces the latter radially outward into engagement with'theedg'es'oi the holes l2- while at the same timeexe'rtin'g a' binding action between thdforinirigstem and the tubular rivet. The axial movementoi the forming stem through thetubular:shankis-facilitated by the fact that thelpitch of :the threads l5 corresponds to the pitch" of the threaded portion 13. ,Finally, a r'everserotation is imparted tonthe driving member 20 topermit the chuck ii to be disengaged iromithe serrated end portion l l of the stem 9. In the embodiment of the invention illustrated in-Figs. 3 and 4, the construction and method of applying the rivet is substantially similar to that above described. In this instance, however, the outer. end portion of the forming stem is bent at right angles, as indicated at 24, for insertion intoan open-ended socket 25, extending radially outward from the axis of an actuator member 26; La'Ihe latter, is slidable axially within a casing 21 having at its forward ,end a concave nose portion;28 for receiving the head 8 of the tubular rivet..jAs in-the case of the pulling device of Fig; ,2, a combined rotational and axial force is applied to the actuator 26. Upon the completion of the-setting operation,'the bent end portion 2 of the forming stem is sheared off as indicated at 29. Rupture of the forming stem at the end oi-the riveting operation is desirable in that it providesa definite indication to the operator that tlie'rivet has been headed; and provision for such rupture by a. shearing action has been found to be advantageous because it permits of an accurate determination of the amount of force necessary to be applied to insure best results. It will be understood that the bent end portion 24 facilitates chucking of the forming stem both for purposesof axial as well as rotational movement.

While I have shown and described the preferred embodiment of my invention, I do not desire to be limited to any of the details of construction shownand described herein, except as defined in the appended claims.

I claim:

i. In an apparatus for setting blind rivets of the type including a rivet body having a shank v adapted to be extended through an aperture into which the rivet is to be set. and a stem having an-upsetting head at one of its ends and radially extending helical threads on the stem to threadedly engage the interior of the shank, which comprises a tool body member, an actuator member movable within said tool body toward and away from one end of said tool body, means on the end of said tool body for engaging the rivet head when the stem is inserted into said tool body, means on said actuatorfor engaging the inserted end of the rivet stem, and means for moving the actuator relative to said body with a combined axial and rotary motion.

2. In an apparatus for setting blind rivets 0fthe type including a rivet body having a shank adapted to be extended through .an aperture into which the rivet is to be set, and a stem having an upsetting headat one of its ends and radially extending helical threads on the stem to threadedly engage the interior of the shank,.which comprises a tool body member, an actuator member movable within said tool body toward and away from one end of, said tool body, means on the end of said tool body for engaging the rivet head when the stem is inserted into said tool body, means on said actuator for engaging the inserted end of the rivet stem, and means for movingv the actuator relative to said body with acombined axial and rotarymotion, the relation between the axial and rotary motions of said actuator and tool body corresponding to the 'pitch of the threads on said rivet stem. j

3. In an apparatus for setting blind rivets of the type including a rivet body having a shank adapted to be extended through'an aperture into which the rivetis to be set, and a stem having an upsetting head at one of its ends and radially extending'helicalthreads on the stem to threadedly engage the-interior of the shank, which comprises a tool body member,;an actuator member movable within said tool body toward and away from one'end of said tool body, means on the end of said tool body for engaging the rivet head when the stem is inserted into said tool body, means on said actuator. for engaging the inserted end of the rivet stem, means threadedly interconnecting said actuator and said tool body having a pitch corresponding to the pitch of the threads on said rivet stem-whereby relative rotary motion imparted between said tool body and said actuator will impart an axial movement and a rotational movement to saidrivet stem to cause the threads onsaid stem to cut corresponding threads in the shank of the rivet body. M

,. ERNEST SHAFF. 

